Food-borne trematodiases affect hundreds of millions of people, particularly the rural poor in the developing world. Since vaccines are currently unavailable, and are unlikely to become available anytime soon for the prevention of food-borne tremotodiases, effective drugs are the only practical means of morbidity control. Importantly, new drugs for these diseases are urgently needed as praziquantel and triclabendazole are the only drugs available and the development of resistance cannot be ignored, particularly in view of the large- scale use of praziquantel in many endemic countries. At the root of this project is our discovery that several synthetic peroxides also possess strong trematocidal activity. We propose to further explore the potential of synthetic peroxides as novel trematocidal drugs. The identification of a new, broad-spectrum, orally-active synthetic peroxide trematocidal drug development candidate will minimize drug-resistance and lead to superior treatment and control options for food-borne trematodiases. Essential characteristics of a new drug development candidate include an economically-feasible and scalable synthesis, excellent oral activity, low potential for toxicity and resistance development, broad spectrum of trematocidal activity, and high efficacy against all parasite stages in the vertebrate host. More specifically, our objective is to identify a drug development candidate with 100% worm burden reductions against juvenile and adult F. hepatica and C. sinensis at doses of < 100 mg/kg and with an excellent ADME profile (predicted ER < 0.30, CYP450 IC50s > 25 5M, oral BA > 30%). To address this overarching objective, we propose the following three specific aims: Specific Aim 1: To synthesize and characterize a focused and structurally diverse library of synthetic peroxides. Specific Aim 2: To assess trematocidal activity and selectivity of target synthetic peroxides against two major human food-borne trematode species, Fasciola hepatica and Clonorchis sinensis. Specific Aim 3: To determine metabolism and pharmacokinetic parameters and initiate mechanism of action studies for selected synthetic peroxides. PUBLIC HEALTH RELEVANCE Food-borne trematodiases, caused by infection with liver flukes, affect hundreds of millions of people, particularly the rural poor in the developing world. Since vaccines are currently unavailable, and are unlikely to become available anytime soon for the prevention of these diseases, new drugs are urgently needed. Praziquantel and triclabendazole are the only drugs now available and the development of resistance cannot be ignored, particularly in view of the large-scale use of praziquantel in many endemic countries. In this proposal, we propose to identify a new broad-spectrum orally-active trematocidal drug development candidate. [unreadable] [unreadable] [unreadable]